Saccade dynamics before, during, and after saccadic adaptation in humans.

PURPOSE When saccade amplitude is systematically inadequate relative to the desired target position, the saccadic system adaptively modifies the amplitude of subsequent saccades so as to recover precise targeting capabilities. The effect of saccadic adaptation on saccade metrics (amplitude, direction) is well documented, but the effect on dynamics (velocity, duration, acceleration, deceleration) remains to be fully elucidated. METHODS The dynamics of adapted saccades were compared with that of baseline saccades of similar amplitudes. RESULTS The peak deceleration and skewness (duration of the acceleration period/duration of the deceleration period) were modified by adaptation. CONCLUSIONS The results point toward involvement of the cerebellum rather than the brain stem saccade generator in human saccadic adaptation.